What is a hard, white, painless bump on a gum? This one has been on my gum for about a month. I stabbed it with a needle and nothing happened. I am going to a periodontist in a week or so but I was just wondering if anyone here has ever had the same thing. I am fairly confident it isn't a canker sore since it is painless. short white lace wedding dress Stephanie Merrill is a badass mouth expert. What do you think?